TV out on the GF3 is kinda whacked, I have Gainward GF3 Powerpak 3, with VIVO. You cannot run monitor and TV at the same time. The Image output is not as good as it should be. I have tested TV out on quite a few GF3 cards. seems this is a Nvidia limitation.
I have not tested the hydra on the Radeon 8500 yet to the TV. It would be an advantage for ATI if they enabled the monitor to work while tv output is selected.